1. Field of the Invention
The invention relates generally to electrical connectors that connect multiple wires together, or that connect one or more wires to other electrically-conductive equipment. More specifically, the invention relates to a connector that comprises an electrically-conductive spiral for being tightened around conductive, stripped wire(s), wherein crimping is not required. In a loosened configuration, the conductive spiral is larger in diameter than the diameter of the stripped wire(s) being inserted into the spiral, but, after said insertion, the conductive spiral is manually tightened into a smaller-diameter configuration that creates electrical contact between said conductive spiral and the stripped wire(s). The preferred conductive spiral receives multiple stripped wires, and, upon tightening, forces said multiple, stripped wires into electrical contact with each other and with the spiral. One spiral, or multiple spirals in series, may be used, and the wires may enter the spiral(s) from the same direction or from opposite directions, wherein the spiral(s) is/are adapted for electrical connection of the wires only to each other. Alternatively, the spiral(s) may be adapted for electrical connection of the wire(s) to a terminal end, such as an eyelet or a fork, that is integral with the spiral(s) and that may, in turn, be connected to another conductive device.
2. Related Art
Crimp connectors are popular electrical connectors that comprise at least one conductive cylindrical portion that is manually crimped (bent, smashed) against a wire inserted into the cylindrical portion. See FIGS. 15-17. An electrically-insulating sleeve typically surrounds the cylindrical portion. Some crimp connectors, typically called “butt splice” crimp connectors, include two, opposing generally cylindrical ends that each receive, and is crimped onto, a wire, for electrically connecting two wires. Said two generally cylindrical ends are integral parts of the single conductive member. See, for example, FIG. 14. Other crimp connectors comprise one cylindrical end for being crimped and an opposing utility terminal end, such as an eye, a fork, or other preferably flat shape for being captured between the head of a screw or bolt and the surface of said another conductive device, or other shapes such as a female or male quick-connect (and quick-disconnect) connector, including rectangular-tubular female (see FIG. 17) or cooperating blade male terminal end, and cylindrical or partial cylindrical female terminal ends or cooperating male pin terminal ends, and other utility terminal ends.
In each of these crimp connectors, the only fastening of the connector to the wire is done by crimping the wall of the generally cylindrical end(s) with a crimping tool to force portions of the wall against or into the wire. The quality of the crimping, that is, the amount and permanence of the contact between the wall and the wire, varies greatly depending on the skill of the person doing the crimping. Further, a crimped connection between wall and wire comprises, at best, a small surface area of the wall abutting and/or gouging into a small surface area of the wire, said small surface area being portions or points around a circumferential surface of the wire only along a very short axial length of the wire.
Prior art crimp-connection devices frequently fail because inadequate pressure is used during crimping. Also, sometimes, the crimping action may “smash” the tubular portion of the connector rather than bending the tubular wall inward; such smashing tends to open the tubular wall at an axial seam, with at least one seam edge moving away from the wire, and, hence, reducing the integrity and effectiveness of the connector. A further problem of such conventional crimp connectors is that is it not always easy to determine the quality and permanence of the crimped connection by visually inspecting the crimp.
An alternative conventional electrical connection may be called a “threaded wire connector,” such as is illustrated in FIG. 18. Such a device may be described as a cap with internal threads tapering from large diameter at an outer end of the cap to smaller diameter at an inner end of the cap. As the threaded wire connector is pushed and turned onto the end of multiple wires, the threads of generally the same diameter as the combined diameter of the multiple wires become screwed around the surface of the wires and/or at least grip and compress the wires. Thus, even though the wires do not originally have any threads on their surfaces, the threaded wire connector enters into a type of threaded engagement with the metal of the wires, gripping and electrically connecting the wires. The threaded wire connector may be screwed off of the wire in the opposite direction.
Only some of the threads of the threaded wire connector grip or gouge into the wires. Thus, engagement between the threaded wire connector and the wires comprises threads along a short axial distance of the threaded wire connector gripping a short axial length of the wires. The larger diameter threads typically do not contact, or at least do not gouge or grip, the wire. The diameters of the threads of the threaded wire connector do not change before, during, or after use on the wire. The threads of the threaded wire connector do not move relative to each other. For examples of threaded wire connectors and/or threaded connectors, see FIG. 18 and also the following patents: Swanson U.S. Pat. No. 3,497,607, issued in 1968; Scott U.S. Pat. No. 4,104,482, issued in 1978; Duve U.S. Pat. No. 4,531,016, issued in 1985; Blaha U.S. Pat. No. 4,707,567, issued in 1987; Blaha U.S. Pat. No. 4,803,779, issued in 1989; Miller, et al, U.S. Pat. No. 4,924,035, issued in 1990; Braun, Jr. U.S. Pat. No. 5,260,515, issued in 1993; Soni, et al U.S. Pat. No. 5,331,113, issued in 1994; Delalle U.S. Pat. No. 5,418,331, issued in 1995; and Market U.S. Pat. No. 5,975,939, issued in 1999.
The patent literature also comprises spring connectors that work by a user forcing a rigid pin or rod into the center space of a spring that has an internal diameter significantly smaller than the diameter of the rigid pin or rod. Said forcing of the pin/rod causes the spring to expand its diameter and it is this expansion of the spring diameter, and the consequent tight fit, that causes the spring to grip the pin/rod. For example, see Fortin U.S. Pat. No. 1,657,253; Hubbell, et al. U.S. Pat. No. 2,521,722; Williams U.S. Pat. No. 4,632,496, issued in 1986; and Bauer, et al. U.S. Pat. No. 6,773,312. Many of these spring connectors are designed so that rotating the rigid pin/rod may be done to loosen the spring's grip on the pin/rod for removal of the pin/rod.
The patent literature also comprises strain relief devices that support and/or reinforce insulation-covered electrical cords, for example, a distance from a conventional plug or other convention electrical connection, to protect the electrical cord from being damaged. See for example, Burkhardt U.S. Pat. No. 1,858,816; Klump, Jr. U.S. Pat. No. 2,724,736; and Rottman U.S. Pat. No. 3,032,737; and Long U.S. Pat. No. 4,632,488. These strain relief devices typically comprise flexible covers or sleeves that surround only insulated portions of a wire/cable, and that do not form any type of electrical contact or play any role in electrical conduction.
There is still a need for an electrical connector that quickly and reliably connects wires to each other, or wires to a terminal end that is then bolted/screwed to a conductive surface. In view of the millions or billions of such electrical connections that must be made every year in the construction, utility, computer and information technology (IT), automotive, and other electrician and IT trades, such an electrical connector should be economical, compact, and preferably permanent. There is a need for a connector, and a need for methods of installing the connector, wherein the installer may be certain that a secure and permanent connection with a large electrical contact surface area may be made. The present invention meets these and other needs.